1. Technical Field
The present invention relates to a projector.
2. Related Art
A projector that has a light source device, an optical modulator for modulating the light beam irradiated by the light source device in accordance with image information and a projection optical device for projecting the light beam modulated by the optical modulator is known.
When dust, lampblack and the like are adhered on a surface of the optical modulator of the projector, image quality of the projected image is deteriorated. Further, since the optical modulator such as a liquid crystal panel in general is weak against heat, the optical modulator is likely to be degraded by heat-generation on account of the light beam irradiated from the light source device.
In order to ensure stable image quality of the projected image and efficiently cool the optical modulator, a mechanism has been proposed, where an optical modulator is disposed within a sealed structure and the air inside the sealed structure is circulated by a circulation fan (see, for instance, JP-A-2000-162708).
No component for cooling the air inside the sealed structure is provided in the mechanism described in the above document. Instead, a sealed box, a head and pipe members constituting the sealed structure are provided by metal material, so that the heat of the air inside the sealed structure is radiated to the outside through the metal components. According to the mechanism, however, it is difficult to secure sufficient heat-radiating area and efficiently cool the air inside the sealed structure. In other words, it is difficult to efficiently cool the optical components such as the optical modulator and the like.
Accordingly, there has been a demand for a technique that can ensure stable image quality of projected image for a long time and efficiently cool the optical components such as the optical modulators.